These are the settings and steps needed to install the Cart Sync theme app extension — the app embed and app block behind Cart Assist — in a merchant's Shopify store. Once installed, cart changes made from the Apptile dashboard (or the customer's checkout) sync live between the storefront and the mobile app.
Step 1 — Get Cart Assist Enabled
Cart Assist must be enabled from the backend before it can be used.
Contact support@apptile.com to have it enabled for the store.
Step 2 — Activate the Cart Sync App Embed
In the Shopify admin, go to Online Store → Themes → Customize → App embeds.
Toggle the Cart Sync app embed (provided by Apptile) on.
Click Save.
Step 3 — Add the Checkout UI App Block
Still in the Theme Editor, go to Pages → Checkout and new customer accounts → Thank You.
In the left panel, open the Sections tab and click Add app block.
Select checkout-ui (provided by Apptile) from the app blocks available for this page.
Click Save.
Step 4 — Create the Required Customer Metafield Definitions
In the Shopify admin, go to Settings → Custom data → Customers.
Click Add definition and create these two definitions exactly as below (double-check the namespace and key — a mismatch here will break the sync):
Apptile Cart Assist Id — Namespace and key:
Apptile-CartAssist.smart_cart_id. Type: Single line text. Storefront access & Customer accounts access: Read & Write.Apptile Cart Assist Checked out Carts — Namespace and key:
Apptile-CartAssist.smart_cart_checkedout_ids. Type: JSON. Storefront access & Customer accounts access: Read & Write.
Step 5 — Use Cart Assist from the Apptile Dashboard
Log in to the Apptile Dashboard and go to Integrations → Cart Assist.
Search for the customer and open their profile.
View or modify their cart — click Checkout Link to copy a link to send them, or Modify Cart to add items, change variant/quantity, then click Save Cart.
Step 6 — Test
Modify a cart from the dashboard (or from checkout) and confirm the change reflects on both the storefront and the mobile app.
Note: Cart Assist requires desktop access to the Apptile Dashboard, and needs Apptile support to enable the feature on the account before Steps 2–5 will work.
